A Primer On Stratified Sampling: Definition, Benefits, And Examples  

A Primer On Stratified Sampling: Definition, Benefits, And Examples  

All marketing and sales strategies aim to grab your target audience’s attention. But how do you actually define your target audience? And what if you could know all your potential clients from that target group? This is where stratified sampling comes in; it’s a tried-and-true method of contacting prospective clients. 

This article will give you a clear understanding of everything you need to know about this technique and how you can utilize it in your business.  

What Is Stratified Sampling?  

The stratified sampling definition refers to a technique of dividing a population into homogeneous strata or groups. It is also known as random quote sampling. 

Each stratum is divided by its common characteristics or attributes depending on your research requirements. Factors such as gender, race, marital status, and income can be used to classify the strata. A representative sample from various social groups should be surveyed randomly to get valuable results. 

Here’s a quick stratified sampling example to help you better understand:  

Assume you want to find out how likely two people with comparable educational backgrounds and marital status will get hitched.  

In this case, the strata will be defined according to gender, allowing you to build two sub-groups or strata: Female and Male.  

As a next step, we must obtain random information from both strata in equal proportions. This will help you compare the educational qualifications of married women and men and conclude your research.  

Related: Probability And Non-Probability Sampling 

Steps To Getting Started With Stratified Sample Formulas 

The numbers on stratified sampling are usually based on the researchers. In short, you don’t need a specific formula to select the target audience, divide the population into different strata or determine the sample size.  

However, the sample sizes for two or more levels of strata may be calculated with the help of the formula shown below. 

Stratum Sample Size: Subgroup Population * (Total Sample Size/Total Population) 

So, to recap, if you wish to take random samples of 100 people and there are 800 girls and 1,200 men, the total number of people is 2,000. 

And, if you use mentioned stratified sampling equation, you’ll need 40 females [100 * (800/2000)] and 60 males [100 * (1200/2000)] to collect the final sample.  

Related: Everything You Need To Know About Subgroup Analysis 

How to Perform Stratified Sampling 

While this might seem complicated at the start, if you follow the steps below, you’ll be able to do this technique the easy way.  

1. Know Your Target Groups  

Knowing your target group type is crucial before collecting samples. It is not just about group identification that needs to be done. You must also understand their behavior to divide the group into proper strata.  

For instance, if you are targeting school students, you can divide them into multiple strata like gender, grade, academic accomplishments, age, interests, or subjects chosen by them.  

The crux is knowing everything about your target group to ensure a proper sampling process.   

2. Determine The Strata 

Once you have your in-depth analysis of the target group, it’s time to choose an interest and divide the entire group based on that particular choice.  

For instance, if you are recording information on girl education, you might also be required to divide the female students based on how educated their parents are. Depending upon your requirements and the scope of research, you can create multiple strata.  

3. Decide On The Sample Size 

You must first decide the sample size to use the stratified sample equation above. This digit will depend upon your research objectives or target population.  

Sample sizes will vary depending on your target market, so they will not always be in digits. However, the ratio of sample size from each stratum must be proportional.  

4. Use The Formula 

The next step is to create a random sample figure based on the fixed sample size that you have determined. You can use the stratified sample formula stated above to calculate the random sample size.  

5. Let’s Begin The Survey 

Now that you have covered all stratified samples, it is time to move on to the real analysis. Using the market research survey software offered by SurveyPoint, you may collect data from large samples and immediately examine the findings. 

This method removes the burden of compiling and interpreting the survey data off your team’s shoulders. Select the appropriate survey type, fine-tune the questions, hit “submit,” and wait for the outcomes. In addition, they can do in-depth statistical analyses of the replies received, both collectively and separately.  

Is that intriguing? You can try out our fully functional demo for free. Get started today by signing up for free. 

Is Stratified Sampling Right For You?  

Stratified sampling can be a great technique to get an unbiased analysis of your target groups in an organized way. But will this technique work for your research objectives?  

Explore the pros and cons of this sampling technique to find out.  

Upsides of Stratified Sampling  
  • Access To Diversified Population: By utilizing this technique, you can simultaneously capture and summarize all your target group’s characteristics. This can offer diversity to your data collection technique and help you gather important insights, which otherwise won’t be possible.  
  • Unbiased Conclusions: This technique is perfect for eliminating biases. The data you get can help you do your research better by providing you with reasonable, unbiased information.  
  • Reliable Conclusions: Stratified sampling allows you to gather important information from different sub-groups evenly. This will enable you to get meaningful outcomes.  
  • Efficient: Not only does this technique save time, but it also helps you stick to your budget. It makes data collection and gathering easy and fast.  
  • Allows For Comparison: The greatest advantage of this technique is that you can compare different patterns recorded from different sub-groups and target the segment that is most suitable for you.  
Drawbacks of Stratified Sampling  
  • Limited Scope: Some studies are not suitable for this methodology. This approach may not be optimal in situations when reliable data on the typical actions of the intended audience is lacking.  
  • Complicated Process: For those unfamiliar with data collecting, identifying the market, learning about the market’s qualities, and segmenting the market based on habits or traits is a challenging process. 
  • Limited Population: When working with a limited sample size, stratified sampling is the way to go. But if you’re planning on doing massive research, you should probably choose a different method. 


One thing you must understand about this sampling technique is creating homogeneous sub-groups. The grounds for dividing the population into sub-groups should be mutually exclusive. Additionally, you should avoid giving too much attention to one subgroup unless it is necessary for your research.  

Heena Shah – Content Writer at Sambodhi

Heena Shah
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